The WN server supports a number of searching methods. Here
is the HTML4.0 Internet draft specification (consisting of 39 files)
as a demonstration of context searching and and an index to the
specification with over 1100 entries made by the WN utility
wnindexmaker.

These are the C language source files for the server proper. You can
browse or search them if you are curious about the server internals.
To download the source use ftp://ftp.acns.nwu.edu/pub/wn/wn.tar.gz.